In the first step, I don´t want to block students to send messages to teachers, Students only should be able to send to Teachers and Admin (Office)
So the options I need are the following:
– Students can send messages only to Admin (office) and Teachers, but not to groups (that will be the different groups of students)
– Teachers can send messages to any individual account (teachers and students) and to the groups (to be able to send the same message to all of them)
– Admin (office) can send messages same as teachers

Please any help.